Christians on the Left, formerly known as the Christian Socialist Movement (CSM), is a socialist society in the UK. The movement fulfils a need among Christian socialists for an organisation that would be both politically engaged and theologically reflective.
The CSM was an amalgamation of the Society of Socialist Clergy and Ministers and the Socialist Christian League. Founded in 1960, it affiliated to the Labour Party in 1988. It was a volunteer organisation until 1994 when it appointed a co-ordinator, followed by an administrator. In August 2013, it announced that, following a consultation with its members, it would be changing its name to Christians on the Left.
R. H. Tawney made one of his last public appearances at the Movement's inaugural meeting on 22 January 1960.
Donald Soper chaired the Movement until becoming its President in 1975.
Christians on the Left is a member organisation of the International League of Religious Socialists.